hwmon: (pmbus/max31785) Add dual tachometer support

[linux-2.6-block.git] / drivers / hwmon / pmbus / max31785.c

diff --git a/drivers/hwmon/pmbus/max31785.c b/drivers/hwmon/pmbus/max31785.c
index 8706a696c89a6c840ebd65d51d33272cf05a2d0c..bffab449be3989821a5bebd0025181a7b9736399 100644 (file)
--- a/drivers/hwmon/pmbus/max31785.c
+++ b/drivers/hwmon/pmbus/max31785.c
@@ -16,9 +16,79 @@
 
 enum max31785_regs {
        MFR_REVISION            = 0x9b,
+       MFR_FAN_CONFIG          = 0xf1,
 };
 
+#define MAX31785                       0x3030
+#define MAX31785A                      0x3040
+
+#define MFR_FAN_CONFIG_DUAL_TACH       BIT(12)
+
 #define MAX31785_NR_PAGES              23
+#define MAX31785_NR_FAN_PAGES          6
+
+static int max31785_read_byte_data(struct i2c_client *client, int page,
+                                  int reg)
+{
+       if (page < MAX31785_NR_PAGES)
+               return -ENODATA;
+
+       switch (reg) {
+       case PMBUS_VOUT_MODE:
+               return -ENOTSUPP;
+       case PMBUS_FAN_CONFIG_12:
+               return pmbus_read_byte_data(client, page - MAX31785_NR_PAGES,
+                                           reg);
+       }
+
+       return -ENODATA;
+}
+
+static int max31785_write_byte(struct i2c_client *client, int page, u8 value)
+{
+       if (page < MAX31785_NR_PAGES)
+               return -ENODATA;
+
+       return -ENOTSUPP;
+}
+
+static int max31785_read_long_data(struct i2c_client *client, int page,
+                                  int reg, u32 *data)
+{
+       unsigned char cmdbuf[1];
+       unsigned char rspbuf[4];
+       int rc;
+
+       struct i2c_msg msg[2] = {
+               {
+                       .addr = client->addr,
+                       .flags = 0,
+                       .len = sizeof(cmdbuf),
+                       .buf = cmdbuf,
+               },
+               {
+                       .addr = client->addr,
+                       .flags = I2C_M_RD,
+                       .len = sizeof(rspbuf),
+                       .buf = rspbuf,
+               },
+       };
+
+       cmdbuf[0] = reg;
+
+       rc = pmbus_set_page(client, page);
+       if (rc < 0)
+               return rc;
+
+       rc = i2c_transfer(client->adapter, msg, ARRAY_SIZE(msg));
+       if (rc < 0)
+               return rc;
+
+       *data = (rspbuf[0] << (0 * 8)) | (rspbuf[1] << (1 * 8)) |
+               (rspbuf[2] << (2 * 8)) | (rspbuf[3] << (3 * 8));
+
+       return rc;
+}
 
 static int max31785_get_pwm(struct i2c_client *client, int page)
 {
@@ -62,9 +132,30 @@ static int max31785_get_pwm_mode(struct i2c_client *client, int page)
 static int max31785_read_word_data(struct i2c_client *client, int page,
                                   int reg)
 {
+       u32 val;
        int rv;
 
        switch (reg) {
+       case PMBUS_READ_FAN_SPEED_1:
+               if (page < MAX31785_NR_PAGES)
+                       return -ENODATA;
+
+               rv = max31785_read_long_data(client, page - MAX31785_NR_PAGES,
+                                            reg, &val);
+               if (rv < 0)
+                       return rv;
+
+               rv = (val >> 16) & 0xffff;
+               break;
+       case PMBUS_FAN_COMMAND_1:
+               /*
+                * PMBUS_FAN_COMMAND_x is probed to judge whether or not to
+                * expose fan control registers.
+                *
+                * Don't expose fan_target attribute for virtual pages.
+                */
+               rv = (page >= MAX31785_NR_PAGES) ? -ENOTSUPP : -ENODATA;
+               break;
        case PMBUS_VIRT_PWM_1:
                rv = max31785_get_pwm(client, page);
                break;
@@ -157,11 +248,15 @@ static int max31785_write_word_data(struct i2c_client *client, int page,
 #define MAX31785_VOUT_FUNCS \
        (PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT)
 
+#define MAX37185_NUM_FAN_PAGES 6
+
 static const struct pmbus_driver_info max31785_info = {
        .pages = MAX31785_NR_PAGES,
 
        .write_word_data = max31785_write_word_data,
+       .read_byte_data = max31785_read_byte_data,
        .read_word_data = max31785_read_word_data,
+       .write_byte = max31785_write_byte,
 
        /* RPM */
        .format[PSC_FAN] = direct,
@@ -208,13 +303,46 @@ static const struct pmbus_driver_info max31785_info = {
        .func[22] = MAX31785_VOUT_FUNCS,
 };
 
+static int max31785_configure_dual_tach(struct i2c_client *client,
+                                       struct pmbus_driver_info *info)
+{
+       int ret;
+       int i;
+
+       for (i = 0; i < MAX31785_NR_FAN_PAGES; i++) {
+               ret = i2c_smbus_write_byte_data(client, PMBUS_PAGE, i);
+               if (ret < 0)
+                       return ret;
+
+               ret = i2c_smbus_read_word_data(client, MFR_FAN_CONFIG);
+               if (ret < 0)
+                       return ret;
+
+               if (ret & MFR_FAN_CONFIG_DUAL_TACH) {
+                       int virtual = MAX31785_NR_PAGES + i;
+
+                       info->pages = virtual + 1;
+                       info->func[virtual] |= PMBUS_HAVE_FAN12;
+                       info->func[virtual] |= PMBUS_PAGE_VIRTUAL;
+               }
+       }
+
+       return 0;
+}
+
 static int max31785_probe(struct i2c_client *client,
                          const struct i2c_device_id *id)
 {
        struct device *dev = &client->dev;
        struct pmbus_driver_info *info;
+       bool dual_tach = false;
        s64 ret;
 
+       if (!i2c_check_functionality(client->adapter,
+                                    I2C_FUNC_SMBUS_BYTE_DATA |
+                                    I2C_FUNC_SMBUS_WORD_DATA))
+               return -ENODEV;
+
        info = devm_kzalloc(dev, sizeof(struct pmbus_driver_info), GFP_KERNEL);
        if (!info)
                return -ENOMEM;
@@ -225,6 +353,25 @@ static int max31785_probe(struct i2c_client *client,
        if (ret < 0)
                return ret;
 
+       ret = i2c_smbus_read_word_data(client, MFR_REVISION);
+       if (ret < 0)
+               return ret;
+
+       if (ret == MAX31785A) {
+               dual_tach = true;
+       } else if (ret == MAX31785) {
+               if (!strcmp("max31785a", id->name))
+                       dev_warn(dev, "Expected max3175a, found max31785: cannot provide secondary tachometer readings\n");
+       } else {
+               return -ENODEV;
+       }
+
+       if (dual_tach) {
+               ret = max31785_configure_dual_tach(client, info);
+               if (ret < 0)
+                       return ret;
+       }
+
        return pmbus_do_probe(client, id, info);
 }